1. Field of the Invention
The invention relates to a liquid crystal display (LCD), and in particular to a color filter substrate thereof.
2. Description of the Related Art
Conventional LCDs comprise a color filter substrate, an array substrate, and a liquid crystal layer disposed therebetween. Formerly, the distance between the substrates was defined by ball spacers. However, no method existed to regulate distribution thereof, so use of a patterned photoresist layer as a spacer became popular.
Conventional large color filter substrates include black matrices between different color filters, with middle or small color filter substrates serving in overlap regions of different color filters as black matrices. As shown in FIGS. 1A and 1B, the color filter substrate includes red, green, and blue color filters 10R, 10G, and 10B on a substrate 11, wherein the color filters overlap to form the overlap regions 12A and 12B. FIG. 1B is a section view of line X-X′ in FIG. 1A, defining the overlap regions. The thickness of overlap regions 12A and 12B is influenced by the overlap of two color filters. To ensure spacers have uniform height, spacers are preferably formed beyond the overlap region. For example, the spacer 14 is formed in the corner of transparent region of the color filter 10R in FIG. 1A. Thus, spacer 14 formed in transparent region of any color filter will reduce aperture ratio of the color filter. If the spacer 14 is directly formed in the overlap region 12A or 12B, the overlap difference of color filters 12R, 12G, and 12B will result in different heights of spacers 14. Thus, a method is called for forming uniform height spacers without reducing aperture ratio.